First published in summer 2010, this is still my most financially successful app. Total downloads across platforms exceed 150,000. CardDroid Math started as a simple multiple-choice math flash cards app with intelligently chosen multiple-choice options. Initially its unique feature was recorded children’s voices giving encouraging messages in response to correct answers. As the app landscape changed, I upgraded the app to offer multiple color schemes, multiple sound sets, and eventually tracking of missed questions, total practice time, and performance.
I also added simple games as rewards after getting a perfect score and added problem sets aligned to the Common Core education al standards being adopted by many states.

Below are some screen shots. They’re cropped into squares so please click to see the whole picture.

Main Play Screen

After getting a problem wrong, that answer is disabled and the child gets another chance.

Horizontal Layout (in Pink)

Problems can be laid out as vertical cards or horizontal “number sentences.” Also, this is “pink dream,” one of a number of selectable color schemes.

Settings Screen

This is the main settings screen with a flag to help new users know where to start, (It goes away after a few times in the settings screen.)

Common Core Built-Ins

Dozens of built-in problem sets, including 10 that are Common Core-aligned to fit with a set of curriculum standards being used by many U.S. states.

Customization Screen

Customize a problem set to exactly exactly what a child needs

A History Report

One of several “history reports” that help parents, teachers, and tutors track kids’ progress.

Doodle Color Scheme

Kids can unlock this “doodle” theme after 60 minutes of total practice time. And it doesn’t count idle time. 🙂